This invention relates to a window for coupling electromagnetic energy through a wall, and between two waveguides, particularly between two environments such as a high pressure environment and a low pressure environment, the window having two panes spaced apart by a quarter wavelength for inhibiting reflection, and having a construction permitting easy disassembly for replacement of components for adapting the window to different frequencies of radiation.
Windows are used for coupling radiation, both electromagnetic and acoustic radiations, between different environments and between different conduits of radiation, such as between two waveguides. Of particular interest herein is the construction of a window for electromagnetic radiation. The window is to be suitable for use in satellite communications wherein alignment and test of the satellite electronics is to occur in a laboratory on the earth while the satellite electronics may be mounted within a vacuum chamber to simulate the environment of outer space. It is, therefore, necessary to provide a window capable of withstanding differences in environmental conditions, such as differences in pressure, and to have a construction suitable for joining waveguides passing through a wall separating the two environmental regions. Furthermore, for accurate testing of the satellite electronics, the window should prevent the generation of reflected waves of radiation, and should have a form of construction which facilitates interchanging of window components for tuning the window to operate in different frequency bands of microwave radiation.
A problem arises in that presently available windows to not provide all of the foregoing desirable features, so that a compromise is necessary in selecting a window for use in a laboratory test situation. This unnecessarily complicates the test procedure and may decrease the attainable accuracy in measurements of the satellite signal processing capabilities.